Method of treating corrosive gaseous fumes or smoke.



UNITED STATES PATENT OFFICE.

CLARENCE B. S PRAGUE, OF SALT LAKE CITY, UTAH, ASS IGNOR TO UNITED STATES SMELTING, REFINING 86 MINING COMPANY, A CORPORATION OF MAINE.

METHOD OF TREATING CORROSIVE GASEOUS FUMES OB SMOKE.

N Drawing.

To all whom "it may concern:

Be it known that I, CLARENCE B. Srnaoun, a citizen of the United States, residing at 360 Center street, Salt Lake City, in the county of Salt-Lake and State of Utah, have invented certain new and useful Improve ments in Methods of Treating Corroslve Gaseous Fumes or Smoke; and I do hereby declare the following to be a full, clear, and

.10 exact description of the invention such as will enable others skilled in the art to which it appertains to make and use the same.

The invention relates to the treatment of corrosive gaseous fumes or smoke such as are produced in theroasting or other treatment of sulfid ores for the purpose of removing from the smoke valuable metals and metallic compounds, or compounds and substances which might be injurious to vegetable and animal life if allowed to escape into the atmosphere.

It is well known that the gaseous fumes or smoke produced in the treatment of sulfid ores, especially the sulfid ores of copper and lead having a high per cent. of sulfur, contain large quantities of sulfur dioxid which exists in the smoke in a gaseous state. It is believed that this gas in the dilute condition in which it exists after having been dis- I so charged into the atmosphere, does not seriously injure the surrounding vegetation, and it is not the purpose of the present invention 'to remove this gas from the smoke. The -smoke produced in the treatment of many sulfid ores, either because of the composition of the ore or because of the character of the treatment to which the ores are subjected, also contain more or less sulfuric acid and other corrosive compounds which exist in 40 the gaseous products as a vapor or in a finely divided liquid or solid state held in suspension. These minute particles of con densed sulfuric acid and other soluble corrosive compounds collect upon the particles of solid matter known as fume, which are always present in the smoke, and are deposited with the fume upon the surrounding vegetation when the smoke is discharged into the atmosphere, and have an 1n ur1ous corrosive action upon such vegetation. The

solid fume, in addition to valuable metals and metallic compounds, also frequently contains poisonous compounds of arsenic and other substances which not only are injurious to vegetation but also render any Specification of Letters Patent.

Patented Feb. 1d, 191i.

Application filed April 7, 1908 Serial No. 425,836.

vegetation upon which they may collect unfit for food or fodder.

It is the object of he present invention to remove the corrosive constituents and fume from the smoke produced in the roasting and other treatment'of such sulfid ores so that the smoke may be discharged into the atmos phere Without injury to the surrounding vegetation, and any values contained in the fume may be reclaimed if desired.

In cases where the gaseous fumes or smoke produced in the treatment of ores are free from sulfuric acid and other corrosive compounds, it has been the practice to some extent to remove the fume by filtration through cotton or woolen bags for the pur pose of recovering the values contained in the fume. It has heretofore been considered impracticable to successfully. filter the smoke.

the smoke with the corrosive acid particles.

At the temperature best suited for the filtration of gases through Woolen bags or other filtering fabric, there is no deposition of moisture, and therefore the neutralizing fume is unaffected by the non=corrosive sulfur dioxid in the smoke, and need be present only in comparatively small quantities. Such temperature is however below the condensing point of sulfuric acid, and the sulfuric acid contained within the smoke will therefore be condensed, and will exist in minute particles held in suspension in the smoke. These fine particles come into intijmate relation with the fine particles of the neutralizing fume which are floating about in the smoke and unite with the neutralizing particles to. form non-corrosive compounds. The acidity of any acid salts held in suspension inthe smoke will also be neutralized by the'neutralizing fume, and any soluble salts of heavy metal, such as iron or that the smoke I of the ore will copner, which may have become moist or adhesivc. and would have a destructive or corrosive action upon the filtering fabric, will be decomposed by the neutralizing fume, and non-corrosive compounds formed.

1e corrosive acid compounds in the smoke will therefore be completely neutralized, so

through fabric without injury to the fabric, or be discharged into the atmosphere.

zinc oxid fume With'the smoke. oxidfume may be produced by fine particles of zinc oxid ume, and non-corrosive compounds formed. into contact with all the minute particles of corrosive acid compound and unite with these to prefer, however, tojemploy an ore or substance which during the treatment of the charge Will produce a zinc oXid,

especially effective in neutralizing the sulfuric acid and other corrosive compounds produced in the treatment of the main body of ore. In roasting or otherwise treating which are of such a composition that the smoke produced would under the usual pracof a zinc ore, which, during the treatment produce ZlIlC oxid fume intermingled with the gases and fumes from the mam body of the ore under treatment. I

have found that in such case the particles or may be successfully filtered corrosive.

oresfume of zinc oxid which are produced in the treatment of the ore either combine With the corrosive compounds simultaneously with their production, or remain in suspension' in the smoke as it passes through the fines and are brought into intimate relation effectively neutralize such compounds so that the smoke when cooled I he passed through filtering fabric is non- Comparatively large quantities of sulfuric acid and corrosive compounds which would otherwise be present in the smoke may be'thus neutralized by combining with the ore to be treated an ore consmoke as it comes to contain no corrosive filtered through the thereto. By this treatment, therefore, metals, metallic compounds, and poisonous an "injurious compounds contained within the fume, and the corrosive and injurious compounds held in suspension, are removed a minimum, and the solid fume is collected so that any values contained therein may be reclaimed if desired by quent treatment.

aving thus described the 1s claimed is 1. The method of removing injurious or valuable compounds from smoke produced in the treatment of sulfid ores, consisting in v neutralizing the smoke by adding to the charge tobe treated a substance which durmg the treatment of the charge will produce 2; The metho of to t e charge tobe treated a substance which during the treatment of the ore will zinc oxid fume for neutralizing the corrosive compounds produced from the main body of ore, and then filtering the smoke to remove the fume, substantially as described. 3. The method of neutralizing the corrosive constituents of corrosive gaseous fumes or smoke consisting With a neutralizing non-corrosive compounds, substantially as described.

Ill)

Correction in Letters 4. The method of neutralizing the corrosive constituents of corrosive gaseous fumes r smoke consisting in intermingling therewith zinc oxid fume which .is held in suspension therein in the smoke and unites with the orrosive compounds to form non-corrosive compounds, substantially as described.

5. The method of treating corrosive gaseous fumes orsmoke for the purpose of removing injurious or valuable compounds therefrom consisting in mingling neutralizing fume With the smoke to neutralize the corrosive compounds therein and thereafter passing the smoke through a filtering fabric to remove the fume, substantially as Patent should be read with this i record 'of the case in the Patent Office.

[SEAL] Signed and sealed this 21st day of March, A. D., 1911.

6. The method of treating corrosive gaseous fumes or smoke for the purpose of removing inj urious or valuable compounds therefrom consisting in, mingling zinc OXlLl fume with the smoke to neutralize the corrosive compounds therein, and thereafter passing the smoke through a filtering fabric to remove the fume, substantially as described. I

In testimony whereof I affix my signature, in presence of two witnesses.

CLARENCE B. SPRAGUE.

Vitnesses:

WILLIAMI M. BRADLEY, VILLIAM PIscrmL.

granted February 14, 1911,

Page 2, line 20,v the words described.

5: i It is hereby certified that in Letters Potent No. 984,498, g; upon the application of Clerence B. Spregue, of Salt Lake City,Utah, for an improverhent in Methods of Treating Corrosive GaseousFumes or Smoke, an error appears i i in the printed specification requiring correction as follows: .2 i fume, and non-corrosive compounds formed, should be stricken out and the Words l fame as Meg float alongiinjlw smoke come inserted instead; and that the said Letters correction therein that the same may conform to the n. nMooRn,

Correction in Letters 4. The method of neutralizing the corrosive constituents of corrosive gaseous fumes r smoke consisting in intermingling therewith zinc oxid fume which .is held in suspension therein in the smoke and unites with the orrosive compounds to form non-corrosive compounds, substantially as described.

5. The method of treating corrosive gaseous fumes orsmoke for the purpose of removing injurious or valuable compounds therefrom consisting in mingling neutralizing fume With the smoke to neutralize the corrosive compounds therein and thereafter passing the smoke through a filtering fabric to remove the fume, substantially as Patent should be read with this i record 'of the case in the Patent Office.

[SEAL] Signed and sealed this 21st day of March, A. D., 1911.

6. The method of treating corrosive gaseous fumes or smoke for the purpose of removing inj urious or valuable compounds therefrom consisting in, mingling zinc OXlLl fume with the smoke to neutralize the corrosive compounds therein, and thereafter passing the smoke through a filtering fabric to remove the fume, substantially as described. I

In testimony whereof I affix my signature, in presence of two witnesses.

CLARENCE B. SPRAGUE.

Vitnesses:

WILLIAMI M. BRADLEY, VILLIAM PIscrmL.

granted February 14, 1911,

Page 2, line 20,v the words described.

5: i It is hereby certified that in Letters Potent No. 984,498, g; upon the application of Clerence B. Spregue, of Salt Lake City,Utah, for an improverhent in Methods of Treating Corrosive GaseousFumes or Smoke, an error appears i i in the printed specification requiring correction as follows: .2 i fume, and non-corrosive compounds formed, should be stricken out and the Words 0..-

l fame as Meg float alongiinjlw smoke come inserted instead; and that the said Letters correction therein that the same may conform to the n. nMooRn,

Correction in Letters Patent No. 984,498.

It is hereby certified that in Letters Patent No. 984,498, granted February 14, 1911,

upon the application of Clarence B. Sprague, of Salt Lake City, Utah, for an improvernent in Methods of Treating Corrosive Gaseous Fumes or Smoke, an error appears in the printed specification requiring correction as follows: Page 2, line 20, the Words fume, and non-corrosive compounds formed, should be stricken out and the words finite as Meg float along int/w smoke come inserted instead; and that the said Letters Patent should be read with this correction therein that the same may conform to the record of the case in the Patent Office.

Signed and sealed this 21st day of March, A. D., 1911.

E. B. MOORE,

Commissioner of Patents.

[SEAL] 

